A man in the case of the locked away Dutch family has been arrested on suspicion of kidnapping, the Algemeen Nederlands Persbureau (ANP) reported.
According to prosecutors as cited by AFP, the man is suspected of "illegal deprivation of liberty" of a Dutch farm family.
"In the investigation, the man is currently suspected of being involved in illegal deprivation of liberty and harming the health of others," Dutch prosecutors said in a statement, adding that he would appear before an examining magistrate on Thursday.
Five siblings aged between 18 and 25 and a 58-year-old man were found in a secret room on the farm near Ruinerwold in the Dutch northern province of Drenthe. According to local mayor Roger de Groot, the man is not the father of the children.
The Austrian foreign ministry earlier said an Austrian national was being held in relation to the case but said the man did not want to have contact with Austrian officials. However, Dutch prosecutors did not confirm the suspect's nationality.
The family had spent nine years "waiting for the end of time", media reports say. According to RTV Drenthe news station, the local police were alerted on the situation after the oldest of the children from the locked away house visited a village bar last week and asked for help.